Re: Super Simple Tacho
I'm getting 1900 rpm at idle and the engine revs to 3500 when serious vibration starts.
Basically, these motors will give good service life using plain old cheap mineral oil at 20:1 using 98 octane unleaded to compensate for the octane lowering properties of 20:1 oil/fuel ratio, but avoid the 100 octane fuels that have ethanol - it attracts water.
I've written an extensive post on the other site about this and cover castor oils ect.
One simple tip for good reliability - apply a verly light application of grease to the helical drive gears every 100 kilometers, DO NOT OVER REV PAST 3500 RPM and use 20:1 together with 98 octane fuel.